This invention relates to an arrangement for shifting optical images between individual channels.
Such an arrangement can, for example, serve to observe individual sections of a field of view or other individual objects by each an optical system in individual optical channels and to guide in fast sequence the detected images to a common optical channel and, for example, to an image-resolving sensor located in the common optical channel. This is the function of an "optical multiplexer". However, such an arrangement can also serve to guide an image generated in the common optical channel to individual parallel channels. This is the function of an "optical demultiplexer".
Prior art arrangements of this type operate with rotating polygon mirrors. One disadvantage of such arrangements is that shifting only can be effected in one single sequence exactly predetermined. A further disadvantage is image blurring due to the movement of the polygon mirror. This image blurring limits the rotary speed of the polygon mirror and, thus, the possible shift frequency (multiplex rate).
Other prior art arrangements operate by displacing elements of the imaging optical system. Such displacement of elements of the imaging optical system also limits the multiplex rate due to the moments of inertia and the inertial forces of the elements to be displaced.
Furthermore, it is known to image individual objects through individual optical channels or paths and a common lens system upon a single detector, the individual optical channels or paths being shifted individually. This requires a large numerical aperture of the common lens system. In addition, problems arise due to scattered light. EP-A-0 469 293 describes a micro-mechanical mirror system having a plurality of electrically actuated mirror elements. A similar micro-mechanical mirror system is described in EP-A-0 657 760.